1 Reply Latest reply on Mar 10, 2016 5:06 PM by diego.medrano

    Correct Calculated Field for Graphs to Update when Using Different Filters?

    Johnson Chao

      Hi all,

       

      I have encountered a roadblock and was wondering if anyone here could help me.

       

      Using Tableau Public, I have been working on the following visual:

       

      https://public.tableau.com/views/HeatStressVisibleNDVIRadishesFebruary242016batchplantedFebruary122016_0/Dashboard1?:emb…

       

      As you can see, I have two comparison "images" that have been processed differently. I have selected and made sets to act as plots for each image, and I want to see how the histograms above change when I use the filter to look at a specific area.

       

      My issue is that while I am able to get the histograms and calculations above to update when I was working with one image, when I have two images the method does not work any more. This makes sense as the underlying data, the RGB values of each pixel with respect to its parent image, are different.

       

      The issue presents itself if you were to deselect all "NDVI" and toggle "Visible" selector—nothing happens in terms of the graphs.

       

      So my question is: how do I go about in writing a calculated field so that the histograms above recognize that I am referring to a selected set of one image and not the other?

       

      Thanks for your time.